"Landmine Sweeper" is a fantasy name for a robot that simply

      detects black bricks on flat lighter surfaces, collects and stores them

      in its large compartment.

It moves around as a differential drive robot, with a Tribot-like caster wheel.

The grabber mechanism is driven by a motor,

      that closes the rubber-fingered claw and rises it to stock the "mine";

      then opens the claw and brings the arm down again.

The light sensor is used to detect black objects on the surface,

      while the ultrasonic sensor detects if robot is going to fall down from the table,

     activating a backup procedure.

Additional material

CAD rendering of the Landmine Sweeper

Video of the Sweeper detecting a table edge (1,14MB)

Video of Landmine Sweeper collecting bricks (3,27MB)

Video of Sweeper grabbing a brick (754KB)